1. Technical Field
The present invention relates to arming devices for weapons and more specifically to a modular electronic safe arm device.
2. Discussion
Explosive warheads used in missiles, bombs add projectiles utilize a safe arm device which prevents the inadvertent explosion of the warhead. Rocket motors often use a similar device to prevent inadvertent ignition of the rocket propellant. These devices vary widely in their design and implementation but share two common characteristics. They use external signals or internal sensors to establish an "arming environment"; that is, they arm only when the weapon has been intentionally launched for a lethal mission. Secondly, they provide a mechanical block of the explosive train separating devices which contain sensitive primary explosives from the less sensitive secondary explosives contained in boosters and warheads.
Recent explosive technology has made it possible to directly initiate secondary explosives with short, high voltage, high current pulses of electricity. These initiation devices are called "exploding foil initiators" (EFI). Since these EFIs contain only insensitive secondary explosives, they make it possible to build an all electronic safe arm device by eliminating the mechanical block separating the sensitive primary explosive. The safeing function is performed by an electronic circuit that prevents the charging of a high voltage firing capacitor which is essential to the function of the EFI. As long as no charge is present on the firing capacitor, the electronic safe arm device remains safe and cannot initiate an explosive or propellant.
In recent years, several electronic safe arms have been designed for use in missiles and bombs. These devices have been adapted to particular applications and have contained electronic circuits typically containing a microcomputer to sense arming environments and when a safe separation environment has been established to charge the high voltage firing capacitor, thus arming the EFI. While these electronic safe arms have certain common characteristics, they have been implemented with different circuits and different physical configurations to suit the specific application.